Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32H7x5_CM7/OTG1_HS_DEVICE/OTG_HS_DIEPTSIZ6#0x0
OTG_HS device endpoint transfer size register
Transfer size
Packet count
Multi count
https://github.com/cmsis-svd/cmsis-svd-data